1. Field of the Invention
The present invention relates to a method for manufacturing flat plate with a precise bulkhead, flat plate with a precise bulkhead, method for manufacturing plasma display unit substrate used for highly accurate and inexpensive large-screen color display units, etc., and plasma display unit substrate.
2. Description of the Prior Art
The plasma display unit used for thin type large screen color display units, etc. has a construction in which opposite electrodes are installed in the space surrounded with bulkheads called microscopic display cells, and the space is sealed with dischargeable gas such as noble gas, etc., and plasma is generated by discharges between opposite electrodes, and the phosphor is allowed to emit light by the plasma to use it as a light emitting element of the screen.
Typically, as shown in FIG. 12, a substrate 105 comprises a large number of bulkheads 102 formed on the whole surface of the back face plate 101. Each space 103 between bulkheads 102 is designated as a cell. Electrodes 104 are placed on the bottom surface of each cell 103. With respect to this substrate 105, phosphor is applied to the inner wall surface 106 of the cell 103, whereas the front panel 108 with the electrodes 107 is joined with the bulkheads 102 of the substrate 105, and gas is sealed in the cell 103 to form a plasma display unit. The electrodes 104, 107 are, in actuality, arranged in such a manner to intersect each other at right angles, but in FIG. 12, they are arranged in parallel for description.
Now, in manufacturing the substrate 105 for the plasma display unit, first a large number of electrodes 104 are formed on the back face plate 101 then the bulkhead 106 is formed between each electrodes 104. Manufacturing methods of bulkheads 106, such as the print lamination method, additive method, sandblast method, and photosensitive paste method are well known.
The print lamination method is to print to form a bulkhead 102 of a specified pattern on the back face plate 101 by the thick film printing method using pastes of the material comprising the bulkhead 102, and since the thickness formed by one printing is about 30 .mu.m, the bulkhead 102 which requires about 200 .mu.m height is formed by repeating printing and drying (see Japanese Non-examined Patent Publication No. Hei 2-213020).
The additive method is to apply photosensitive resin on the back face plate 101, to curve grooves by the light on the photosensitive resin, and to embed pulverized glass in the groove to form the bulkhead 102.
In addition, the sand blast method is to form a glass layer of a specified thickness on the whole surface of the back face plate 101, on this surface, to form the resist mask in the form of the bulkhead 102 and then, to remove the glass layer of the portion other than the bulkhead 102 by sandblasting (see Japanese Non-examined Patent Publication No. Hei 4-259728).
In addition to this, the photosensitive paste method is to apply the paste with photosensitive resin mixed on the back face plate 101, and after masking, to irradiate light to directly form the bulkhead 102.